I’m assuming this is a new equipment purchase, and that you configured it, and that you did not purchase this equipment used and already configured.
Your MacBook Pro will have whatever username and login password you set up when you configured macOS.
If you do not recall what password you set up for your login, you can override that by specifying your Apple ID and password, if your login is (as would be typical) associated with your Apple ID.
Change or reset the password of a macOS user account - Apple Support
Mac permits multiple users, and each has their own login, password, home directory, settings, etc.